Method of and apparatus for printing



Nov. 14, 1950 s. R. BRODIE ET AL METHOD OF AND APPARATUS FOR PRINTING Filed Oct. 26, 1948 FIG.

Patented Nov. 14, 1950 METHOD OF AND APPARATUS FOR PRINTING George R. Brodie, Lower Merion Township, Montzomery County, and William M. Hawkes, Jr.,

Philadelphia, Pa., ass'ignors to Fredk H. Levey Co.,lnc., New York, N. Y., a corporation of New York Application October 26, 1948, Serial No. 56,656

1 This invention relates to printing and particularly to an improved method of and apparatus for supplying ink to the metal printing plates of cylinder presses.

, In Web presses, it has been customary for many years to deliver ink from the fountain to the plates on a plate cylinder through a long train, upward to twenty, of inking rollers which rotate and vibrate in order to provide a uniform film of ink on the printing plates. The complicated mechanism required in the usual ink train materially retards the possible speed of operation of the press and consequently its output.

It is the object of the present invention to provide an improved method of inking the plate cylinder of a rotary printing press and apparatus therefor which is simpler and more eifective and which permits operation at higherspeeds.

Other objects and advantages of the invention will be apparent as it is better understood by reference to the following specification and the accompanying drawing, in which Fig. 1 represents diagrammatically the essential parts of the inking and printing mechanism; and

Fig. 2 is a side elevation of one of the inking rollers.

In accordance with the present invention, we employ an ink of the quick drying type consisting of a pigmented varnish made up of a resin and a solvent therefor which has a relatively low'boiling point and a high vapor pressure at the temperature to which it is subjected for the purpose of drying the ink. Quick drying inks of this type are used extensively in printing magazines and have superseded linseed oil inks during the past sixteen years. Instead of a complicated inking train, we employ a relatively simple arrangement consisting of a hard surfaced rubber roller which contacts the printing plates on the plate cylinder and also a knurled roller to which ink is deliv ered from a fountain through an intermediate ductor roller. The knurling on the knurled roller is disposed at an angle preferably 45 to the line parallel to the axis of the roller. The roller between the knurled roller and the plate cylinder is provided with a hard rubber surface having a hardness of between 30 and 95 Durometer, The ink is picked up from the fountain by a steel roller revolving therein. An adjustable doctor blade is arranged to limit the amount of ink withdrawn from the fountain. The ink is transferred by the intermediate ductor roller to th knurled roller, which receives a uniform film of the ink and transfers it through the hard surfaced roller to 5 Claims. (Cl. 101-350) the plates on the cylinder. The knurled roller has the effect of causing the ink to transfer uniformly and in the correct amount to properly ink the surface of the printing plates and thus to secure an impression of high quality on the web as it passes between the plate and impression cylinders. Owing to the simplicity of the inking train, many of the difliculties experienced in the ordinary press are avoided and the speed of the press may be increased materially.

The knurling on the knurled cylinder may vary in dimensions, but is preferably about 175 lines to an inch with a depth not exceeding 0.002 inch. If the knurling is too coarse, the desired effect is not obtained, but it may be finer than indicated with excellent results. The pressure between the knurled roller and the engaging hardsurfaced roller may vary from a few pounds to 10,000 pounds per square inch. The combination of the knurled roller with the hard surfaced roller ensures the transfer of the ink in the manner already indicated to the plates on the plate cylinder.

For the purpose of the invention, we employ ink of the quick drying type consisting of a pigmented vehicle made up of a resinous binder and a petroleum hydrocarbon having a relatively low boiling point and a high vapor pressure when subjected to a temperature above normal atmospheric temperature. A characteristic ink of this type is mad in accordance with the following formula: 4

2.00 alkali blue base 15.30 zinc resinate 22.60 petroleum hydrocarbon, B. Pt. 450 F.

0.10 water 0.75 gilsonite 0.68 rosin 1.07 petroleum hydrocarbon, B. Pt. 503 F. 3.20 wetting agent (tallicin 105) 16.00 carbon black 6.30 calcium carbonate pigment 32.00 petroleum hydrocarbon, B. Pt. 381 P.

It is to be understood that in describing this typl. cal ink the invention is not thereby limited, because it is apparent that numerous combinations involving substitutions of resins, pigments and other ingredients of the ink may be made. Thus, the ink may be of any desired'color by substituting suitable pigments. There are numerous resins which are adapted to be dissolved in the solvent to produce varnishes suitable for the purby modifying the proportions of the solvent in the composition as above described.

Referring to the drawing, 5 indicates an impression cylinder, and 6 the plate cylinder carrying metallic plates having an appropriate type surface. Theimpression is transferred to a web I which passes between the plate and impression cylinders. Engaging the plates on the plate cylinder is a hard surfaced rubber roller 8 having the characteristic hardness as above described. The roller 8 is engaged by a roller 9 of metal having a knurled surface Of the character hereinbefore described. An intermediate ductor roller of rubber or other suitable material is disposed between and in engagement with the roller 9 and a steel roller l l which is adapted to rotate in a fountain l2 carrying the ink l3. The roller I0 is mounted on an arm I0 which vibrates to alternately engage the roller lu with the roller I l and the knurled roller 9. .A doctor blade II is supported on a bracket I and is adjustable by means of thumb screws It to vary the distance between the surface of the roller H and the edge of the doctor blade in order toJimit the amount of ink withdrawn from the fountain as the roller H rotates in the direction indicated by the arrow on the drawing. Thus, the ink from the fountain is transferred to the intermediate ductor roller Ill, thence to the roller 9 and through the surface of the roller 8 to the printing surface on the plate cylinder. By adjusting the doctor blade H, the amount of ink supplied to the train may be varied. I

The web 1 may be carried around a steam drum or other heating device I1 and over an idler roll l8. It may be rewound after the initial impression. However, if the web is to be perfected by printing on the reverse side, it may be delivered from the idler roll it to a second printing unit identical with that previously described, to receive an impression on the reverse side. Thereafter the web may be heated again by passing over a steam drum similar to the drum I! to dry the ink. The web may then be rewound, cut or otherwise disposed of.

Among the advantages of the apparatus is the relative inexpensiveness of the apparatus and ease of handling of the ink, and particularly the avoidance of long trains of inking rollers as here- 4 tofore used in web printing presses. T e advantage resulting from the elimination of the complicated inking trains is the increased speed at which the printing operation may be carried on. The method and apparatus are adapted for printing of a wide variety Of materials, including books, magazines, newspapers, catalogs, telephone directories and the like.

Various changes may be made in the details of the procedure as described and in the apparatus employed without departing from the invention or sacrificing the advantages thereof.

We claim:

1. The method of inking metallic printing plates which comprises transferring ink from a source thereof to a rotating smooth metal surface, thence to a rubber rotating surface, thence to a knurled rotating surface, thence to a rotating smooth hard rubber surface, and finally to the rotating printing plate surface.

2. The method of inking metallic printing plates which comprises transferring ink from a source thereof to a rotating smooth metal surface, thence to a rubber rotating surface, thence to a knurled rotating surface, thence to a rotating smooth rubber surface having a hardness of to 95 Durometer, and finally to the rotating printing plate surface.

3. In a printing press, a plate cylinder, an impression cylinder and an inking train comprising a fountain, a rotating metal roller adapted to deliver ink from the fountain, a knurled roller, an intermediate ductor roller having a rubber surface engageable with said ink-delivering metal roller and said knurled roller, and a roller having a hard rubber surface, said hard surfaced roller engaging the knurled roller and the plate cylinder.

4. The printing press of claim 3 having a doctor blade adjustable with respect to the surface of said ink-delivering metal roller to control the amount of ink withdrawn by said roller from the fountain.

5. The printing press of claim 3 in which the surface of the hard-surfaced roller has a hardness of 30 to Durometer.

GEORGE R. BRODIE. WILLIAM M. HAWKES, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,056,210 Rowell Oct. 6, 1936 2,213,419 Taylor Sept. 3, 1940 FOREIGN PATENTS Number I Country Date 198,864 Great Britain June 14, 1923 

